Branch trace
Encyclopedia
A computer program
Computer program
A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...

 debugging
Debugging
Debugging is a methodical process of finding and reducing the number of bugs, or defects, in a computer program or a piece of electronic hardware, thus making it behave as expected. Debugging tends to be harder when various subsystems are tightly coupled, as changes in one may cause bugs to emerge...

 tool or analysis technique; An abbreviated instruction trace in which only the (successful) branch
Branch (computer science)
A branch is sequence of code in a computer program which is conditionally executed depending on whether the flow of control is altered or not . The term can be used when referring to programs in high level languages as well as program written in machine code or assembly language...

 instructions are recorded. On IBM System/360 this was implemented as part of Program-Event Recording (PER) but was seldom used at the application programming level. Program Event Recording hardware was used and due to the overhead of this tool, it was removed from customer-available MVS
MVS
Multiple Virtual Storage, more commonly called MVS, was the most commonly used operating system on the System/370 and System/390 IBM mainframe computers...

 systems http://en.wikipedia.org/wiki/MVS#Evolution_of_MVS.

Use

With the availablity and reference to a compiler
Compiler
A compiler is a computer program that transforms source code written in a programming language into another computer language...

 listing of the program together with a branch trace, the full path of executed instructions can be reconstructed. With a lot more effort, the full path can even be reconstructed with a memory dump (containing the program storage) and a branch trace.

Alternatives

A more comprehensive trace of all the instructions (including instructions between branches) can be obtained by the use of an instruction set simulator
Instruction Set Simulator
An instruction set simulator is a simulation model, usually coded in a high-level programming language, which mimics the behavior of a mainframe or microprocessor by "reading" instructions and maintaining internal variables which represent the processor's registers.Instruction simulation is a...

(where available on some platforms). A full instruction trace can provide additional information such as address/length and value of memory alterations.
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